How to deal with a very long-term perspective on an urban system? This communication proposes a possible interdisciplinary approach in a research landscape where multiple viewpoints are practicable, based on archaeology and geography. The aim is to study an urban system from its origins during Antiquity to nowadays. The discussion is based on the case study of Noyon (Picardy, France). This current work inherits from urban archaeology, first developed in England during the 1960’s thanks to the meeting of archaeologists and town planners, and from theories and concepts linked to spatial analysis.